Effects of psychological state on pain perception in the dental environment.

Psychological factors have an important influence on pain perception. Both in the clinic and in experimental settings, distraction has been shown to reduce pain. Further, negative emotions increase pain, whereas positive emotions have the opposite effect. Other more complex psychological states alter the way we feel pain. For instance, empathy for another person who is suffering increases our own pain experience, and expectation of pain relief underlies much of the placebo effect. Neuroimaging studies show a physiological basis for psychological pain modulation, with activity in pain pathways altered by attentional state, positive and negative emotions, empathy and the administration of a placebo. The same psychological factors activate intrinsic modulatory systems in the brain, including those stimulated when opiates are given for pain relief. It is important for the dentist and patients to understand the influence of psychological state on pain transmission. Such an understanding will not only help patients learn how to participate in their own pain control, but will also help the clinician create a fostering environment.